An Israeli banking expert was ready to testify on the bank’s behalf, about how far advanced it was beyond even Israel’s banking practices in complying with the new harsher post-9/11 standards for checking US Office of Foreign Assets Control suspicious persons.

It was ready to bring testimony and public statements by US officials about its free-from- terror connections bona fides.

The bank had won in US federal courts on similar cases and overlapping evidence, including a chart where a judge showed that some of the most egregious fund transfers to terrorists occurred when the they were not yet on official watch-lists.

Jordan, considered a moderate state in a Middle East full of vulnerability to radical Islamist takeover, told the US Supreme Court that the economy of the country, could tank and critical counter-terror cooperation could fall apart if the case goes south.

In this case, the plaintiffs maintain that they have enough smoking-gun evidence directly from the bank, from spin-off official US investigations into the bank and from records the bank has refused to turn over, that they can prove that its “mental state” was to overlook terror funds transfers, even ignoring its own written protocols. The bank has admitted a small number of errors, but is ready with feasible explanations like typographical errors in the names, whereas the plaintiffs say these errors are key to understanding a much broader practice.

Do transfers to “martyrs” mean suicide bombers or could they also be an honorific Islamic reference to deceased persons who were not involved in terrorism? These are judgment calls that will confront a jury for the first time, since big banks from Iran, Lebanon, North Korea and others simply do not show up for court, and default judgments are handed down, which can then never be enforced.

Arab Bank wants to be known as a serious institution in good standing in the West, and is the exception that has shown up and taken the risk of losing big.

If the plaintiffs win, there may be a long line of claimants trying to prove retrospective responsibility using creative forms of circumstantial evidence to trap big banks in informal recklessness, combined with official commitment to anti-terror compliance checks.

If the plaintiffs win, the US government and Supreme Court will need to weigh whether a clear conscience with regard to a relatively large number of victims’ families is worth risking Jordan’s stability and its wider cooperation.

The US government may stop the case at that point, having hoped in vain that it would sink at trial on the massive evidentiary challenge of proving a bank’s “mental state” long ago on a small number of electronic pass-through transfers from an incredible volume.

If Arab Bank wins it will be a piercing defeat to terror finance litigation, which has scared terror funds out of many areas with slogans like “bankrupting terror one case at a time,” but as a movement, has suffered several setbacks of late.

Losing the case, would not kill this industry, but it would poison some of the optimism on the idea that moving beyond default judgments to trials is a winning strategy.

In any event, with all of the pieces in place, Monday’s showdown will be a trial for the ages.